Non-Uniform Solder Bump Layout for Stress-Resistant Packages
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Solution Overview
Problem
Semiconductor packages with reduced solder balls are susceptible to mechanical stress-induced damage due to stress concentration at the remaining solder balls, particularly at corners, which can lead to cracks and failure under external forces.
Innovation Solution
The implementation of non-uniformly sized solder bumps, with larger bumps at corners and smaller bumps elsewhere, designed to distribute mechanical stress more evenly and improve thermal and electrical conductivity, including oval, rectangular, or L-shaped configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the number of solder balls is reduced to achieve smaller package size, then the package size is reduced, but the mechanical stress resistance deteriorates due to stress concentration at remaining solder balls
Solution Approach 1:
The patent applies local quality by making corner solder balls larger than center solder balls. The corner solder balls have a first diameter while center solder balls have a second diameter that is smaller than the first diameter. This local differentiation allows corner regions to bear more mechanical stress while center regions provide electrical connectivity, resolving the contradiction between reduced solder ball count and mechanical stress resistance.
Solution Approach 2:
The patent employs asymmetry by creating non-uniform solder ball distribution across the package substrate. Corner solder balls are intentionally made larger to compensate for their position at package corners where stress concentration occurs during drop tests. This asymmetric design breaks the traditional uniform solder ball pattern and optimizes mechanical strength distribution.
2Strength
If corner solder balls are made larger to improve mechanical stress resistance, then the stress distribution is improved, but the manufacturing complexity increases due to non-uniform solder ball application
Solution Approach 1:
The patent segments the solder ball application process by treating corner and center regions differently. The method involves applying a first amount of solder material at corner locations and a second amount at center locations, where the first amount is greater than the second amount. This segmentation allows for simplified manufacturing compared to individual customization of each solder ball, as it uses area-based material deposition rather than precise individual placement.
Solution Approach 2:
The patent changes the parameter of solder material amount based on location. By controlling the amount of solder material applied (first amount at corners, second amount at centers), the process achieves non-uniform solder ball sizes through a uniform deposition process. This parameter change approach simplifies manufacturing by avoiding complex individual solder ball formation while still achieving the desired size differentiation.
Data Source
AI summary
In some aspects, the disclosure is directed a module for improving mechanical, electrical, or thermal performance. In some embodiments, the module includes a bottom surface, a side surface, a first solder bump disposed on the bottom surface, and a second solder bump disposed on the bottom surface. In some embodiments, the bottom surface extends in a first lateral direction and a second lateral direction perpendicular to the first lateral direction. In some embodiments, the side surface extends in a vertical direction perpendicular to the first lateral direction and the second lateral direction. In some embodiments, the second solder bump is adjacent to the side surface. In some embodiments, the first solder bump has a first length in the first lateral direction. In some embodiments, the second solder bump has a second length in the first lateral direction. In some embodiments, the first length is greater than the second length.